Riddle:

A fair coin is tossed repeatedly.

1. What is the expected number of tosses before HT shows up for the first time?

2. what is the expected number of tosses before TT shows up for the first time?

3. What is the probability that HT shows up before TT?

Python Solution (3 parts):

Riddle Source:

The Colossal Book of Mathematics: Classic Puzzles, Paradoxes, and Problems